Telegraphic receivi ng-instrum ent



(No Model.)

G. SMITH.'

'JBLEGRAPHIG RECEIVING NsTRUMENT.

No. 254,061. Patented Feb. 21,1882.

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guna/wko@ N. PETERS, Pnuxuenugmpmr, wasmngwmpjc UNITED STATES PATENTOFFICE.

GERRlT'I SMITH, OF ASTORIA, NEW YORK.

TELEGRAPHIC RECEIVING-INSTRUMENT.

SPECIFICATION forming part of Letters Patent No. 254,061, dated February21, 1882,

Application filed December 29, 1881. (No model.)

To all whom t may concern Be it known that I, GERRT'I'T Snrrrr, a. citi`zen of the United States, residing at Astoria, inthe county ofQueens andState of New York, have invented certain new and useful Improvements inTelegraphic Receiving-Instruments, of which the following is aspecication.

The general object of my invention is to attain a greater degree ofrapidity and certainty of action in tele-graphic receiving-instrumentsthan has been possible with the apparatus hitherto employed for thatpurpose, and to providean instrument which is especially adapted for useupon long and imperfectly-insulated telegraph-lines orin cases whereunusual rapid- 'ity of signaling is required, and these ends I attain byactuating the moving portion of the receiving-instrument-that is to say,the armature and its attached lever, which produces audible sounds,carries a recording` stylus or pen, or serves to open and close anindependent electric circuit when utilized as a relay or repeater-through the instrumentality ofa constant mechanical power controlled byelectromagnetism, instead ofactuating the armature and its lever, asheretofore, solely by the/direct attractive force of an electro-magnet.

In the accompanying drawings, Figure l is a` plan view ot' an apparatusembodying my invention, part of which is broken away to exhibit theinternal construction; and Fig. 2 is a transverse vertical section takenin the plane of the dotted line 2 2 in Fig. l.

In the drawings, A represents a suitable base upon which the variousparts ofthe apparatus are mounted.

Bis a helix or coil of thin insulated wire, which is wound upon anupright hollow spool or bobbin, b, the lower ange, b', of which ispreferably formed of hard rubber or other' insulating material.

AC is a cylinder of magnetic metal, preferably of soft iron, fittingclosely within the central opening of the hollow bobbin b, but capableof rotating freely upon its axis. The cylinder O forms the core of thehelix B. lt preferably has a flange, c, formed upon its upper end.

From the lower end of the cylinder C projects a spindle, c', upon whichis fixed a small pulley, D, beneath the base A. A belt or band, d,passes around the small pulley D, and also around a large pulley,E,which is also mounted in the same plane underneath the base A, as shownin dotted lines in Fig. l.

A crank, F, is affixed to that portion of the shaft c of the pulley IGwhich projects above the base., by means ot' which crank it may beturned by the hand by the receiving-operator in the direction indicatedby the arrow. When the crank F is thus turned the soft-iron cylinder C,which forms the core of the hollow helix B, is caused to rotate rapidlyin the direction indicated by the arrows in Fig. l.

The upper surface of the cylinder C is polished, and is moreovercarefully turned and ttcd, so as to revolve as aecuratel y as possiblein a horizontal plane.

H is an armature, preferably formed of athin flat disk of soft iron, aportion of the periphery of which rests upon the upper surface of thecylinder G nearthe edge of the flange, as shown in Figs. l and 2. Thedisk or armature H is capable of moving freely in a horizontal planeupon its vertical pivot or axis h; but the extent of this horizontalmotion is limited by a rigid arm or lever, I, which is fixed to thearmature and moves with it, and which plays between fixed stopsJand K.These stops may with advantage be rendered adjustable by means of aset-screw or other well-known or equivalent device, as shown in Fig. l.The stop J is mounted upon a standard, Il, attached to the base A, whilethe stop l is mounted upon a block, Z, secured to butinsulated from thestandard L.

The retractor M consists of a spiral spring attached to the armature IIat a point in its periphery diametricall y opposite to the point ofattachment of the arm I. The retractor may be adjusted by means of themilled head N and spindle n, or other equivalent device, so as to exerta constant force of any required amount upon the armature I.

The helix B terminates in the projecting` wires w fw, which areelectrically connected to the bindingscrews W W2, and serve to form aconnection with the main line.

W'hen the apparatus is to be used as a relay or repeater the armature His electrically connected by means of the wire :r with the bind* ing-post X, and in like manner the standard L is connected by means of thewire y with the IOC biudingpost Y, and the bracket Z may also beconnected by the wire l@with the binding-postZ.

The apparatus thus constructed isplaeed in the circuit of atelegraph-line, the connections being completed in the ordinary mannerby means of a wire, w', connecting the binding postW with the earth atthe receiving-station, while the line-wire 102 coming from thetransmitting-station is attached to the binding-post W2. The key at thetransmitting-station may be arranged to open and close the circuit ofthe main battery T, as shown at Q', or it may be inserted in awell-known manner, as shown at Q2, so' that when closed it will shunt aconstant resistance, It, normally interposed in the line, and thusactsimply to alternatelyincrease and decrease the strength of current inthe line without interrupting the circuit.

The operation of the apparatus is as follows: When atelegraphiccommunication is to be received upon the instrument thecylinder C, which forms the core ot' the coil B, is caused to rotateupon its axis in the direction indicated by the arrows, which maybeeffected by turning the crank F, as hereinbefore explained. So long aslno electric current traverses the coil B the friction between thecylinder C and the armature H, which rests lightly upon it, will be sosmall that the cylinder will have but a slight tendency to drag thearmature along with it, and this tendency will be overcome by theresistance ofthe springN, so that the armature will remain in its normalposition, (shown in Fig. 1,) the arm I resting in contact with the stopK. When, however, an electric current is transmitted through the line,as by the depression of the key Q', the cylinder() instantly becomesmagnetic under the intluence of the coil B and attracts the armature H,which rests upon its periphery. The pressure produced by this magneticattraction increases the friction between the two surfaces to such anextent that the antagonistic force of the retractingspring M isovercome, and the armature H is caused to turn upon its axis by theforce imparted thereto by the friction ot the rotating cylinder-0. Hencethe arm I is brought into contact with the stop J, inwhichpositionitremains as long as the electric currentcontiimes to traversethe coil B.

When the current is interrupted by the raising of the key Q' theattraction between the cylinder C and the armature H ceases and therecoil of the spring M instantly restores the armature and its attachedarm to their normal position.

Incase it is desired to operate the apparatus by an alternate increaseor decrease in the strength of a constant current-as, for examA ple,bymanipulatin g the key Q2-thetension of the retracting-spring M is soadjusted that the friction due to the magnetism induced by the normal orminimum strength of current is not quite sufficient to overcome itstension; but any increase of friction beyond the normal amount willovercome the spring and instantaneously produce a lateral movement ofthe armaturein the manner hereinbei'ore explained.

The apparatus has been shown in the drawings in a form particularlyadapted for use as a relay or repeater, in which case the terminal wiresof an independent receivinginstrument, S, and local batterys areconnected to the binding-screws-X and Y, in which ease the independentcircuit will be closed in the same manner as by the lever of an ordinaryrelay whenever the arm I is brought into contact with the stop J.

lt is obvious that the ordinary telegraphic signals may be distinguishedby the ear upon this instrument in the well -known manner heretoforepracticed by expert telegraphists, the requisite sounds being` producedby the vibration of the arm l between the fixed stops J and K.

I claim as my inventionl. The combination, substantially as hereinbeforeset forth, of arotating cylinder of magnetic metal, a magnetizing-coilacting upon said cylinder, an armature maintained in permanent magneticcontactwith the moving surface of said cylinder and capable of receivingmotion therefrom by friction, a retractor exertin g a constant forceupon said armature in a direction opposed to that derived fromv itsfrictional contact with the moving cylinder, and fixed stops forlimiting the movements of the armature in each direction.

2. The combination, substantially as hereinbefore set forth, of arotating cylinder of magnetic metal, a magnetizing-coil acting upon saidcylinder, an armature maintained in permanent magnetic contact with themoving surface of said cylinder and capable of receiving motiontherefrom by friction, a retractor cxerting a constant force upon saidarmature in a direction opposed to that derived from the movingcylinder, an electric circuit including said magnetizing-helix, and akey or transmitter in said circuit for alternately increasing anddecreasing the strength of the current traversing said circuit.

3. The combination, substantially as hereinbefore set forth, ot' arotating cylinder of magnetic metal, a magnetizing-coil acting upon saidcylinder, an armature maintained in permanent magnetic contact with themoving surface ot said cylinder and capable of receiving motiontherefrom by friction, a retractor exerting a constant force upon saidarmature in a direction opposed to that derived from the movingcylinder, and an independent circuit traversed by an electric currentwhich is controlled by the movements of said armature.

In testimony whereof I have hereunto subscribed my name. this 24th dayof December, A. l). 1881.

GERRITT SMITH.

Witnesses:

FRANK L. Porn, MILLER G. EARL..

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